GMP4 MemCal Hybrid Circuit Info

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Hogflash
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cars: 1984 Volvo 240 Diesel-LT1 powered

GMP4 MemCal Hybrid Circuit Info

Post by Hogflash »

I'm working with the Lotus M100 folks to come up with some replacement MemCals (ECM PN 1228707) but they are pretty much non existent at this point.

Does anyone here have any information or documentation regarding the design of the Hybrid circuitry in the MemCal and what all it controls (i.e. knock and limp home mode and other stuff?) I'm wondering if there is either a suitable replacement from a more popular vehicle, or maybe (given 25 years of advances in IC capabilities) a replacement could be designed. I seem to recall running across a project to do this many (10+) years ago, but not finding anything now.

Thanks,

Gary
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delcowizzid
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Re: GMP4 MemCal Hybrid Circuit Info

Post by delcowizzid »

Should be a long memcal the same as 89-94 Holden Commodore but with different netres for limp home mode .here's the inside of one of the netres for number of cylinder select function and throttle body injection .we turn v6 ones into v8 ones and 4 cylinder and just leave the limp mode stuff as is viewtopic.php?f=11&t=214&hilit=Netres page 2 has all the possible combinations for cylinder selection.
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delcowizzid
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Re: GMP4 MemCal Hybrid Circuit Info

Post by delcowizzid »

Also the same as a all the usa long memcals from 1227165 747 etc
If Its Got Gas Or Ass Count Me In.if it cant be fixed with a hammer you have an electrical problem
Hogflash
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Re: GMP4 MemCal Hybrid Circuit Info

Post by Hogflash »

Has anyone actually traced out the circuit on the ceramic hybrid? This is what I'd like to see so I can understand what it is actually doing, and how to properly adapt it to different vehicles.

I have visually compared the M100 turbo and non-turbo circuits, and the non-turbo is a simple resistor network only, no active components. The Turbo is completely different and looks like the V8 version illustrated in the linked topic.

Gary
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antus
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Re: GMP4 MemCal Hybrid Circuit Info

Post by antus »

Does this help?
Attachments
memcal.pdf
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Hogflash
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Re: GMP4 MemCal Hybrid Circuit Info

Post by Hogflash »

YES!! Now *THATS* more like what I am looking for. This appears to be something used during development for the Lotus Carlton - I don't know what the similarities for the 4-cyl M100 turbo are, but it is a starting point. Now, to figure out what is in the Delco 26500 IC...

Thanks! --Gary
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